3076r On 26/30 Dyno Results And Possible Issues

[Pattygtst]

A new quality actuator will give you better response and control boost better too.

The factory actuator will work, but the spring may be a little weak, causing exhaust gases to "leak", resulting in poorer response (making it more laggy) and the power to feel doughy.

I really should have brought this up sooner. It wasnt something that was easy to search.

I am picking the car up today so it hasnt been dynod yet. It was dam hard getting the stock acuator on there in the first place if i had known or if tuner recommened i would have forked out that little extra to get it right. Fingers crossed it works fine and there is no issues. Would hate for such a small cheap thing to effect it so much.

How hard would it be to remove old one and replace with a quality acuator if i wanted to later?

[Pattygtst]

well i called tuner and the car is getting boost creep. He did infact put on a aftermarket actuator. He is letting mtq know and see what they suggest. My tuner thinks external wastegate is the way to go but i know people here have been successful with holding boost.

in my mind it could be either of these three issues

How large is the waste gate flapper, apparently they made it larger to suit

Split dump used, seems to be a common problem with these turbos

actuator, i assume he choose the required one but who knows

I guess they just go through the scenarios trial and error now. How dissapointing

Just got some more info as i was busy when he called me last and i didnt get all infor

on low boost setting = 10 pounds by the time its hits 7000rpm it goes up to 17 pounds

on high boost setting = 17pounds it holds 17 but fluctuates a bit.

it made 350rwhp at 17psi 18 knock on WA dyno

Edited December 16, 2008 by Pattygtst

[Al]

Hey al, your setup is very nice, do you run an internal gate turbo?

Thanks.

Yep, internally gated turbo.

At the time of buying the turbo (and most other parts for the build) i was going for a stock look, like Cubes has. As time went on i found out that i had to buy a GReddy plenum if i wanted to use a strut brace, things just snow balled, the "stock look" idea was thrown out and an "all out" approach was adopted. The manifold has provisions for an external gate, but i am happy with how the setup is currently performing, so i have no plans, as yet, to upgrade the rear housing and but a external gate.

[Gts-t]

Cheers Al, im still tossin up the idea of a IW 3076R maybe even low mounted.

Im only looking for 300rwkw so im wondering if the ext gate is worth it at that level. I guess i manly have second thoughts because of the trouble i see some have with 6boost style manifolds on one hand and yours and cubes good results on the other.

[Al]

well i called tuner and the car is getting boost creep. He did infact put on a aftermarket actuator. He is letting mtq know and see what they suggest. My tuner thinks external wastegate is the way to go but i know people here have been successful with holding boost.

in my mind it could be either of these three issues

How large is the waste gate flapper, apparently they made it larger to suit

Split dump used, seems to be a common problem with these turbos

actuator, i assume he choose the required one but who knows

I guess they just go through the scenarios trial and error now. How dissapointing

Just got some more info as i was busy when he called me last and i didnt get all infor

on low boost setting = 10 pounds by the time its hits 7000rpm it goes up to 17 pounds

on high boost setting = 17pounds it holds 17 but fluctuates a bit.

it made 350rwhp at 17psi 18 knock on WA dyno

What size is your rear housing?

I have seen the same turbo, with a 0.63a/r housing, on a rb25, boost creep as well. Basically the front and rear ratios are missed matched, causing boost creep.

How tight is the actuator arm? Is it adjustable? The hole on the arm should only miss the flapper mount by about half the hole width. Any more and you may be restricting the movement of the flapper, causing it no to open fully thus unable to bleed off enough exhaust gases.

Also check the the split pipe is not interfering with the flapper movement. Disconnect the actuator and check that the flapper moves freely through its full 90 degree movement.

Also note my low boost is set at 15-16psi (using a 15psi actuator), so if i am getting boost creep it wouldn't show in my setup. I am also using the std flapper that came with the turbo. Just remember you need to bleed off a lot more exhaust gases to maintain 10psi, than you do to maintain 17psi.

My exhaust also has a "bell mouth" at the turbo (not split pipe) which is said to be better for boost control but apparently make a little less power (2-4rwkw)

Hope that helps

[R31Nismoid]

What turbo ID tag patty - thats the key part.

And then the usual questions - are you 100% sure its not a milled housing etc.

Soon as its a modded-to-fit, is when people usually have these problems

[Pattygtst]

Al its a 0.82 housing and has the larger wastegate fapper.

The split was inteferring with the fapper and they put back on the hoist to sort it out.

I dont know what actuator is being used and how its set. I will find out tomorrow and let you know if i am still having probs

Ash i will see if i can get the id tags but they will be the right ones as this was all done through mtq garrett and they knew exactly what was needed as did i.

I think its obviously got to do with the split and maybe acuator.

I will let you know tommorow

I am not concerned it it creeps on low boost i just want it to hold at its best potential up high like 17 psi and above,

Cheers

[unique1]

Brad, with that manifold I made 370hp at 1bar here in perth, so only 15psi, it made 396 on jem's dyno in Sydney (was running your cat in sydney, but was removed for the dyno in perth). The only draw back I can see with that manifold is the small id runners....

Very suprised you guys didnt check/set base timing!!?

Adam, yeh Mick.

Hey Nick, fair enough, looking at the runners merging into the flange that bolts onto the head it isnt very good at all, massive steps and edges sticking into the flange hole areas restricting the flow, i havent got any pics but was considering redoing the flange part again so they are smooth and flow well.

We did check the base timing before the tune and its moved by the looks of it unless my timing light is 10 degrees out compared to the one we used on dyno for some odd reason. I have had issues before with the trigger disk jumping around and altering timing so that could also be a possibility and hence a couple of runs were ok and then the rest were dipping in the middle. I bought a new trigger disk but i been told they are also wrong and need to redrilled to suit my engine.

i havent had time but more dyno runs are in order and sort this out its just not anywhere near the ballpark it should be.

[AD4M]

aftermarket bov on it brad?

mates car had an issue where it was dropping power in the middle of the revs and would slowly recover back but wouldnt make the top end power back, ended up being a leaky bov and with it blocked off it solved all the issues

[unique1]

aftermarket bov on it brad?

mates car had an issue where it was dropping power in the middle of the revs and would slowly recover back but wouldnt make the top end power back, ended up being a leaky bov and with it blocked off it solved all the issues

Adam yes it does have an aftermarket one thats adjustable and i was playing with adjustment days before i got it tuned and unsure exactly what its set to now, you could be on the money, thanks for that ill be checking it now

[Pattygtst]

Good and bad news

Good news, it is not boost creeping, Yay got 390hpaw wa dyno on 19psi

Bad news hit 19psi at 5000rpm wtf? 10psi at 4000rpm. Thats not right is it?

[Pattygtst]

^that is rb25 btw

[Phobic]

wow that seems awfully laggy...

[Pattygtst]

Yeah its unbelievably laggy, where thinking the boost controller now. The eboost 2 is a bit complicated. Might try bleed it first

Any thoughts advice?

[R31Nismoid]

its internal gate ...

just wire the gate shut

you'll soon tell then if its EBC or not

[Adriano]

Is it possible that the adjustable cam wheels have slipped? Thats the only way i can see the timing moving 10deg

[Al]

Hitting 19psi at 4500-5000rpm is pretty normal on an rb25; It is a 500+hp turbo.

[Pattygtst]

i hope your wrong but another guy at the workshop made 19psi by 4400 in this sr20 so i expect better. Seen a few guys here get 19psi by 3800 so i still think it can do much better.

[Al]

An sr20 turbo will have a smaller rear housing, so it may spool a little faster, even though the engine is only a 4cyl.

I wouldn't believe anyone that claims they achieved 19psi by 3800rpm, on a mild rb25, using that turbo.

[dangerman4]

next time i take the 33 out i will get a pic of the hand controller showing boost and revs.

its a 25

same manifold as Als

3582r-iw .82

ive seen 5 psi by 2600rpm on a big hill, and i reckon im around the 4k mark for 24 psi.

i will pay attention and get a pic for you.